The use of flexible straps to secure bundles of wire or cable is well-known. Typical devices using this concept consist of an elongated strap with a lock on one end. The strap is placed around the bundle of wire or cable to be secured, to form a loop, and then the free end of the strap is inserted into the lock and the loop is tightened. The lock generally includes a ratchet arrangement which engages a set of teeth or serations on the free end of the strap. Therefore, once the loop is tightened by drawing the free end of the strap through the lock, the engagement of the ratchet with the teeth or serations maintain the tightened condition. Such devices are commonly referred to as "cable ties".
Cable ties have a number of distinct advantages for securing bundles of wire or cable. Cables ties accommodate bundles of varying sizes and shapes. Thus, a very wide range of bundle sizes and shapes can be secured by a worker with only a few sizes of cable ties in his toolbox. Also, because the loop which secures the bundle is not formed until the worker inserts the free end of the strap into the lock, there is no need to thread the wire or cable through an already-closed loop; the strap is simply looped around the bundle that is to be secured. This also allows the bundle that is to be secured to be easily attached to other elements such as structural members in the vicinity of the wire or cable installation, by simply including those members in the loop where it is formed. Cable ties are also generally made of light-weight plastic so that hundreds of them may weight only a few pounds.
One of the chief advantages of cable ties over other devices for securing bundles of wire or cable is that they can be installed with a tension in the looped strap which ensures a tight and secure installation. The worker simply pulls the free end of the strap tightly through the lock on the other end to diminish the loop size. As he does so, the ratchet in the lock ratchets through the teeth or serations in the free end. When the free end is let loose, it cannot back out of the lock and thereby expand the size of the loop by more than the small distance between adjacent teeth or serations which is generally less than a tenth of an inch.
It has been known for some time that cable ties and similar devices employing flexible straps that are adjustably looped into locks that use one-way ratchets, could be used as cuffs to restrain a person. The simplest way to restrain a person using a cable tie is to loop a single cable tie around the person's wrists and tighten the loops so that the wrists are bound together. This is particularly effective if the person's hands are behind his back. Additional restrain can be established by looping another cable tie around the person's ankles and tightening that loop to bind the ankles together. Law enforcement authorities have used cable ties for this purpose for a number of years in place of traditional metal hand cuffs, because in comparison to metal hand cuffs, cable ties are lightweight and compact. Also, a danger of metal handcuffs is that the person to be strained may break free after one cuff is on but before the second cuff is on, and then the free cuff becomes a deadly swinging weapon.
Devices have also been developed which operate on the basic idea of a free strap looped into a ratcheting lock, but which are specifically configured for restraining a person rather than for bundling wire or cable. For example, U.S. Pat. No. 4,071,023 by Gregory is a restraining cuff with two free straps and two ratcheting locks, so that there is a separate cuff for each of two wrists or two ankles. U.S. Pat. No. 5,088,148 by Burkholder is similar to the Gregory patent in that there are two free straps and two ratcheting locks so that two cuffs can be formed, but the two locks are positioned on a single mount. U.S. Pat. No. 5,099,662 by Tsai includes a mechanism to release the ratchet to allow the device to be re-used. Similarly, U.S. Pat. No. 4,964,419 by Karriker includes a mechanism to expand and contract the cuff size.
A significant drawback to the use of ordinary cable ties as restraining devices is that most of them can be used only once. After the free end of the strap is looped into the ratcheting lock, it is impossible to draw it back out. Therefore, it is necessary to cut the strap with a pair of wire cutters or a similar tool when the restrained person is to be freed. In fact, it is necessary to cut the strap and apply another cable tie if the person is not to be freed but merely because the loop was too tight on the person. Of course, this destroys the cable tie.
There are a few devices which are re-usable such as the Karriker devices mentioned above. However, a drawback to those devices is that they are designed such that the lock can be released without the use of a key so that the strained person himself or someone else without authority can release them. Also in the prior art are ordinary cable ties not specifically designed to restrain a person, that have a tab protruding out of the ratcheting lock to disengage a ratchet pawl from teeth on the strap to release the strap. Such devices have the same limitations as the Karriker device in that there is nothing to prevent unauthorized persons from releasing the device. The Tsai device mentioned above is releasable using a key; however, unlike the present invention, that device is quite complex in its mechanism.